A neutral current transformer is a device located on the neutral bus of a three-phase circuit breaker having a four-wire ground fault scheme and electronic trip unit. The current transformer is used to detect differences between the current flowing through the neutral bus and the three phases. The current transformer must be protected from potential hazards in its immediate environment with some type of sealing enclosure.
Some current transformer assemblies are presently sealed by pouring epoxy resin into a molded cup which houses the transformer, completely surrounding the transformer coil. Epoxy is used because it prevents shock of impact or vibrations from affecting the function of the current transformer. However, using epoxy to encapsulate the current transformer, is a time consuming process, and further prevents subsequent repairs to the transformer.
Another means for encapsulating a current transformer is to fasten two separate enclosures together, using special screws or fasteners. This assembly requires several fastening parts and is a time consuming assembly process.
Accordingly, there is a need for an effective and efficient means for providing a protective enclosure surrounding a current transformer and for providing quick assembly and accessibility for repairs.